I use a lot of 6-32 nylon stand-offs 1/2 to 1” in length.
4-40 will work too.
I moved to (standardized) M2 brass stand-offs in the last two years.
These are readily available and reasonably priced.
They can be purchased from 3mm to 40mm in 1 mm increments.
See this very long thread for Stand-Off ideas: